The present invention generally relates to a temperature monitoring device. More specifically, the present invention pertains to a temperature monitoring device for controlling the temperature of an object, and for possibly also indicating and/or recording abnormal temperature variations. Although not limited in this regard, the device of the present invention can be to observe the temperature conditions of a bearing in operation.
In modern bearing technology, bearings operate best within certain temperature ranges. For different types of bearings and/or different types of bearing applications, this temperature range can vary. During operation, the temperature will vary based on variations in different parameters such as load, speed and amount of lubricant. A rise in the bearing temperature above a certain level can thus provide an indication that there are risks that the bearing assembly may be starting to break down, thus presenting the possibly of causing damage to the machine equipment and/or other components with which the bearing assembly is associated.
Different temperature monitoring devices have been developed over the years, which are often rather complex and expensive, which might incorporate for instance a bimetallic relay, and which following a temperature increase exceeding a certain numeric value, open a valve to permit injection of a small amount of lubricant in the bearing. There are also relatively simple mechanical temperature monitoring devices which, for example, use a spring element having a shape memory effect to visually indicate that the temperature has passed a certain critical temperature level. A significant problem associated with such earlier known temperature monitoring devices, such as those disclosed in U.S. Pat. No. 4,448,147, is that they must be carefully calibrated before use. Also, these devices usually also have an ability to react only when a certain numerical temperature value has been exceeded, but are not sensitive to temperature variations over large ranges insofar as such ranges do not overlap the specified temperature value.
A need thus exists for a temperature monitoring device which is relatively simple in design and relatively easy to install, while at the same time bing quite efficient.
According to one aspect of the invention, a temperature monitoring device for continuously monitoring the temperature of an object includes a housing having contact means engageable with the object for producing heat transferring contact with the object, indicating means for outputting an indication of a temperature condition of the object, a sensing member positioned in heat transferring contact with the contact means to emit a signal representative of a current temperature of the object, and a control device connected to the sensing member to receive the signal from the sensing member representative of the current temperature of the object and to emit a signal to the indicating means to output the indication of the temperature condition of the object. A power supply means supplies power to the control device, the sensing member and the indicating means, and a switch means is urged to a first condition interrupting the supply of power from the power supply means to the control device, the sensing member and the indicating means, and is movable into a second condition causing the power supply means to supply power to the control device, the sensing member and the indicating means. A portion of the housing is movable between a first position in which the switch means is urged to the first condition and a second position in which the portion of the housing contacts the switch means to cause the power supply means to supply power to the control device, the sensing member and the indicating means.
According to another aspect of the invention, a temperature monitoring device for continuously monitoring the temperature of an object includes a housing adapted to be connected to the object, a sensing member sensing a current temperature of the object by way of heat transfer when the housing is connected to the object and emitting a signal representative of the current temperature of the object, an indicator mounted on the housing for outputting an indication of a temperature condition of the object, a processor connected to the sensing member to receive the signal from the sensing member representative of the current temperature of the object and to emit a signal to the indicating means to output the indication of the temperature condition of the object, and a power supply that supplies power to the processor, the sensing member and the indicator. A switch is changeable between a first condition in which power from the power supply to the processor, the sensing member and the indicating means is interrupted, and a second condition in which power is supplied from the power supply to the processor, the sensing member and the indicating means. A mechanism is provided for changing the switch between the first condition and the second condition.
In accordance with a further aspect of the invention, a temperature monitoring device for continuously monitoring the temperature of an object includes a housing adapted to be removably connected to the object and having a contact portion to contact the object in a heat transfer manner, a sensing member mounted on the housing in heat transferring contact with the contact portion of the housing to sense a current temperature of the object by way of heat transfer when the housing is connected to the object and emitting a signal representative of the current temperature of the object, an indicator mounted on the housing which produces an output indicating a temperature condition of the object, and a processor connected to the sensing member and the indicating means to receive the signal from the sensing member representative of the current temperature of the object and to emit a signal to the indicating means causing the indicating means to produce at least a first output indicating the temperature condition of the object. The processor determines a normal operating condition temperature of the object when a steady-state temperature of the object sensed by the sensing member has been reached and determines an abnormal operating condition temperature of the object when the temperature of the object sensed by the sensing member is outside a predetermined range from the normal operating condition temperature. The processor emits a signal to the indicator upon determining the abnormal operating condition temperature of the object so that the indicator produces the first output indicating the abnormal operating condition temperature of the object. In addition, a power supply supplies power to the processor, the sensing member and the indicator.